v1.0.0rc2

What's Changed

• Fix #135 by @auxten in #136

Full Changelog: v1.0.0rc1...v1.0.0rc2

v1.0.0rc1

What's Changed

• Fix changing default database by USE in session mode by @auxten in #133

Full Changelog: v0.16.0rc2...v1.0.0rc1

v0.16.0rc2

What's Changed

• Fix build 0.16 by @auxten in #131

Full Changelog: v0.16.0rc1...v0.16.0rc2

v0.16.0rc1

chdb Release Summary

chdb 0.16 based on clickhouse 23.10

Query Enhancements

• Vector Addition:

  • python3 -m chdb "SELECT [1, 2, 3] + [4, 5, 6]".

• Omit file() Function:

  • python3 -m chdb "SELECT * from '/home/Clickhouse/bench/hits_0.parquet' limit 10".

• NumPy as Input Format:

  • Support for NumPy as an input format with the query SELECT * FROM 'data.npy'.

• Parquet Optimizations:

  • Writing parquet files is 10x faster, it's multi-threaded now. Almost the same speed as reading.
  • Parquet filter pushdown. I.e. when reading Parquet files, row groups (chunks of the file) are skipped based on the WHERE condition and the min/max values in each column.
  • Optimize reading small row groups by batching them together in Parquet.

• Condition Pushdown for ORC:

  • Using data skipping indices in ORC, similarly to Parquet.

• PRQL Support:

  • Added support for PRQL as a query language.

• urlCluster Function:

  • Add urlCluster table function.

New Features

• Introducing arrayFold for applying a lambda function to multiple arrays.
• Extended support for asynchronous inserts with external data via the native protocol.
• Introduced function jsonMergePatch for merging JSON strings.
• Continued support for Kusto Query Language dialect with Phase 1 implementation.
  - Introduced a new SQL function arrayRandomSample for sampling elements from an input array.
  - Added support for dropping cache for Protobuf format with SYSTEM DROP SCHEMA FORMAT CACHE [FOR Protobuf].
• Conditions on arguments of a table with a space-filling curve in its key can now be used for indexing.
• New setting force_optimize_projection_name checks that a projection is used in the query.
• Added aggregation function lttb using the Largest-Triangle-Three-Buckets algorithm for downsampling data.
• CHECK TABLE query has better performance and usability, supporting checking particular parts.
  - Introduced function byteSwap for reversing the bytes of unsigned integers.
  - Added functions formatQuery and formatQuerySingleLine for formatted SQL query output.
  - Introduced DWARF input format for reading debug symbols from an ELF file.
  - Introduced SHOW SETTING setting_name as a simpler version of SHOW SETTINGS.
  - Added fields substreams and filenames to the system.parts_columns table.
  - Introduced a setting create_table_empty_primary_key_by_default for default ORDER BY ().

Performance Improvements

• Fixed contention on Context lock, significantly improving performance for short-running concurrent queries.
• Improved the performance of inverted index creation by 30%.
• Optimized memory consumption for external aggregation with many temporary files.
• Added option query_plan_preserve_num_streams_after_window_functions to preserve the number of streams after evaluating window functions.
• Released more streams if data is small, optimizing resource usage.
• Optimized RoaringBitmaps before serialization.
• Optimized inverted index posting lists to use the smallest possible representation.
• Set a reasonable size for the marks cache for secondary indices by default.
• Avoided unnecessary reconstruction of index granules when reading skip indexes.
• Cached CAST function in set during execution to improve the performance of function IN when set element type doesn't match column type.
• Improved write performance to EmbeddedRocksDB tables.
• Improved overall resilience for ClickHouse in case of many parts within a partition.
• Reduced memory consumption during loading of hierarchical dictionaries.
• All dictionaries now support the setting dictionary_use_async_executor.
• Prevented excessive memory usage when deserializing AggregateFunctionTopKGenericData.
• Reduced CPU consumption for AsyncMetrics threads on a Keeper with lots of watches.
• Experimental inverted indexes now do not store tokens with too many matches, saving space.
• Improved write performance to EmbeddedRocksDB tables.
• Improved write performance to hierarchical dictionaries.

v0.15.0

What's Changed

• Enable hdfs, avro and rapidJson/simdJson by @nmreadelf in #123

Full Changelog: v0.14.2...v0.15.0

v0.14.2

Keep debug info in shared lib

v0.14.1

What's Changed

• Add CHDB_VERSION for cmake by @nmreadelf and @lmangani in #96
• Enable output_format_arrow_string_as_string for default by @nmreadelf in #98
• Strip library/wheels by @lmangani in #99
• Support UDF in Python by @auxten in #100
• Fix minor test coverage by @auxten

Full Changelog: v0.13.0...v0.14.0

v0.14.0

What's Changed

• Add CHDB_VERSION for cmake by @nmreadelf in #96
• Enable output_format_arrow_string_as_string for default by @nmreadelf in #98
• Strip library/wheels by @lmangani in #99
• Support UDF in Python by @auxten in #100

Full Changelog: v0.13.0...v0.14.0

v0.13.0

What's Changed

• Query stats by @auxten in #91

Full Changelog: v0.12.0...v0.13.0

v0.12.0

What's Changed

• Query on multiple Pandas DataFrame by @auxten in #89

Full Changelog: https://github.com/chdb-io/chdb/commits/v0.12.0